It is common practice to purify water for industrial and domestic use by subjecting it to treatment with ozone gas. The same treatment can be applied for purifying gases and other liquids. Ozone is produced by passing oxygen or a mixture of gases containing oxygen, such as air, through a corona discharge established between pairs of electrodes which are separated by an air gap and a dielectric shield, when the electrodes are connected to a high voltage source. Glass is the most common dielectric material used in such generators.
A common type of ozone generator relies upon a corona discharge in the annular space between an inner metal rod and an outer metal tube, with a glass tube interposed between the outer tube and the rod. To avoid excessive heat buildup due to the corona, water or other cooling fluid is used to cool one of the electrodes and the other electrode is cooled by heat radiation to the environment.
An ozone generator acts as a high-potency ion source when it is caused to generate a high frequency corona discharge by applying a high-frequency voltage to an electrode. The electrochemical action is particularly productive when a high voltage with an extremely short pulse is applied to the ozonizer electrode. Examples of ozone generators of the type to which the present invention relates are given in U.S. Pat. Nos. 1,011,503; 3,421,999; 3,677,931; 4,049,552; 4,090,960; 4,176,061 and 4,427,426.